Thirty years of shareholder activism: A survey of empirical research

We summarize and synthesize the results from 73 studies that examine the consequences of shareholder activism for targeted firms, and draw two primary conclusions. First, activism that adopts some characteristics of corporate takeovers, especially significant stockholdings, is associated with improvements in share values and firm operations. Activism that is not associated with the formation of ownership blocks is associated with insignificant or very small changes in target firm value. Second, shareholder activism has become more value increasing over time. Research based on shareholder activism from the 1980s and 1990s generally finds few consequential effects, while activism in more recent years is more frequently associated with increased share values and operating performance. These results are consistent with Alchian and Demsetz' (1972) argument that managerial agency problems are controlled in part by dynamic changes in ownership, and with Alchian's (1950) observation that business practices adapt over time to mimic successful strategies.